However, exciting two pairs of side-bands and their amplification during evolution follows even more complex MI dynamics and cannot be explained by a single breather formulation. Following the principle of nonlinear superposition, two-pair of side band will form a two-breather solution [1]}, [2]}, [3]}, [4]} described by the physics of higher order-modulation instability (H-MI). Recently, a number of studies have been devoted to study their occurrences in real physical systems [5]}, [6]}, [7]}. Particularly, in [5]}, the role of H-MI to form a two breather solution in nonlinear fiber optics has been theoretically discussed with experimental verification.
